With the production and packaging of, in particular, confectionery, for example, large and small chocolate bars, the problem ensues that the production machine is operated continuously for technical production reasons, while the packaging machine or plant is shut down for bridging over intermediate periods. Such intermediate periods can be caused by breaks prescribed for the operatives in the packaging plant or through a fault, for example, changing a roller, at one or several packaging machines in the packaging plant. During all these intermediate periods, the individual products supplied by the production machine must be transferred to a store. The store is then able to be emptied again outside the intermediate periods in that the unpacked individual products are fed to the packaging plant.
A store of the above-mentioned type is known from U.S. Pat. No. 4,168,776. The essential component in this store is an endless chain which is wound around chain wheels. One part of the chain wheels is fixed locally, while other chain wheels, assembled in pairs, are arranged so that they can move vertically. An input station and an output station, separate from said input station, are built onto the store and can be operated independently of each other, i.e. the store can be filled or emptied according to requirements. Therefore, the store can either be just filled or just emptied. In addition, it is possible to empty while filling, whereby completely different speeds can also be used. The known store has a relatively large dead area, i.e. roughly 50% of its volume serves only to merely convey the individual products through the store. Before the first individual item can be picked off again from the output station, the store must be filled to approximately up to half its volume. Only the remaining half of its volume forms the storage line with variable receiving capacity. If one of the essential properties of a store is to be able to allow removal at any time or to make this possible in a relatively short time, then the ratio of storage lines with variable receiving capacity to the ratio of the dead space serving only the conveying is relatively unfavourable. This means that such a store needs to be built relatively long and high if its storage line with variable receiving capacity is to be or needs to be sufficiently large. The endless chain has carrier plates for receiving the individual products and a conveying facility for transporting the carrier plates on the chain in a roughly circular motion through the store is provided, whereby the individual drive wheels form a part of this conveying facility. Owing to the arc-like change of direction of the endless chain at the chain wheels and the step-wise or jog-wise transfer of the chain at the various positions, forces ensue at the change of direction positions which act on the individual products in a direction parallel to the main lengthwise plane of the carrier plates. In order that the individual products do not slip off the carrier plates and drop down, the carrier plates must either have an appropriate shape or other measures must be applied. It is clear that the peripheral speeds at the chain wheels are limited. The performance of such a store is thereby limited.
Stores operating on the same priniciple are known from DE-PS 31 48 473, DE-AS 17 56 268 or also from DE-AS 25 02 386. The advantages of these stores are that the input station and the output station can be operated independently of each other. Furthermore, these stores have a speciality in that the individual products can be removed again in the same sequence as they were fed in, i.e. the first individual item fed into the store is the first one to be taken out again.
For applications involving the storing of confectionery, in particular large and small chocolate bars, it is known, based on the principal arrangement of the store described above, to use gondolas which are connected via an articulated joint with the endless chain. These gondolas have a certain number of carrier plates above one another, for example, five carrier plates, whereby each carrier plate is designed and built to receive a row of confectionery items. The separation between the carrier plates within a gondola is, therefore, smaller than the distance of the lowest carrier plate of a first gondola from the uppermost carrier plate of a following gondola. The larger difference at this point is designated as a gondola jump. On the other hand however, this enables the gondolas to be able to negotiate the change of direction at the chain wheels, whereby the carrier plates always remain in the horizontally-aligned position. As the naked, unpacked items of confectionery are slid onto flat carrier plates, it is not possible to vary the shape of the carrier plates. The articulated suspension of the gondolas allows, on the one hand, the change of direction around the chain plates and on the other hand, the negative influence of the accelerating forces upon further movement of the endless chain is reduced. The disadvantage with such gondolas is that the steps in which the endless chain moves to the next stage, for example, in the area of the input station, must be large. The larger path corresponds to the gondola jump and this gondola jump thereby determines the performance of the store because this movement represents the greatest load (stress) on the items of confectionery. No item of confectionery may fall from the carrier plate at the gondola. To bridge over the separation between the carrier plates of a gondola, a similarly large timespan as with overcoming the gondola jump is ready, so that a comparatively low speed can be used here.
The other disadvantage of such stores equipped with gondolas is that owing to the way the change of direction is effected, the store needs to be built very large although its storage line with variable receiving capacity is relatively small. The sliding of the confectionery items onto the carrier plates in the area of the input station and the sliding off from the carrier plates in the area of the output station puts corresponding loads on the items of confectionery because sliding friction has to be overcome here. Incidentally, the push-on process must be so performed that the item of confectionery lies symmetrical about the hinge point of the gondola, or rather a vertical plane which passes through this hinge point. This means that with alternating confectionery formats, different paths have to be traced during the push-on process and/or carrier plates and gondolas matched to the format and shape of the respective case in question need to be used on such stores.
A further disadvantage is that all gondolas in the store must be moved during certain operating conditions. For example, this is the case when a completely empty store with respect to its dead space, i.e. with respect to its storage line with constant receiving capacity, is to be filled.
Furthermore, it is a disadvantage that with the known stores, the carrier plates fixed to the gondolas can only be cleaned with difficulty. This is practically impossible during normal, continuous production. Only if the store and the associated plant is shut down is it possible to carry out tedious cleaning.